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    <title>zpell</title>
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    <center>Scilab Function</center>
    <div align="right">Last update : April 1993</div>
    <p>
      <b>zpell</b> -  lowpass elliptic filter</p>
    <h3>
      <font color="blue">Calling Sequence</font>
    </h3>
    <dl>
      <dd>
        <tt>[zeros,poles,gain]=zpell(epsilon,A,omegac,omegar)  </tt>
      </dd>
    </dl>
    <h3>
      <font color="blue">Parameters</font>
    </h3>
    <ul>
      <li>
        <tt>
          <b>epsilon</b>
        </tt>: real : ripple of filter in pass band (<tt>
          <b>0&lt;epsilon&lt;1</b>
        </tt>)</li>
      <li>
        <tt>
          <b>A</b>
        </tt>: real : attenuation of filter in stop band (<tt>
          <b>A&gt;1</b>
        </tt>)</li>
      <li>
        <tt>
          <b>omegac</b>
        </tt>: real : pass band cut-off frequency in Hertz</li>
      <li>
        <tt>
          <b>omegar</b>
        </tt>: real : stop band cut-off frequency in Hertz</li>
      <li>
        <tt>
          <b>zeros</b>
        </tt>: resulting zeros of filter</li>
      <li>
        <tt>
          <b>poles</b>
        </tt>: resulting poles of filter</li>
      <li>
        <tt>
          <b>gain</b>
        </tt>: resulting gain of filter</li>
    </ul>
    <h3>
      <font color="blue">Description</font>
    </h3>
    <p>
    Poles and zeros of prototype lowpass elliptic filter.
    <tt>
        <b>gain</b>
      </tt> is the gain of the filter</p>
    <h3>
      <font color="blue">See Also</font>
    </h3>
    <p>
      <a href="ell1mag.htm">
        <tt>
          <b>ell1mag</b>
        </tt>
      </a>,&nbsp;&nbsp;<a href="eqiir.htm">
        <tt>
          <b>eqiir</b>
        </tt>
      </a>,&nbsp;&nbsp;</p>
    <h3>
      <font color="blue">Author</font>
    </h3>
    <p>F.D.   </p>
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